Variability is the extent to which data points in a statistical distribution or data set diverge from the average, or mean, value as well as the extent to which these data points differ from each other. There are four commonly used measures of variability: range, mean, variance and standard deviation.

​What Is Bias?​A bias is a tendency. Most biases—like the preference to eat food instead of paper clips—are helpful. But cognitive shortcuts can cause problems when we're not aware of them and apply them inappropriately, leading to rash decisions or discriminatory practices. Stereotype threat, for example, is the confirmation of negative stereotypes about another person's race, gender, group, and so on. Relying on biases but keeping them in check requires a delicate balance of self-awareness.